What is it?
A general and steady decline in all areas of mental ability, usually caused by a brain disease.
Over time, people with dementia suffer from some of the following symptoms:
- memory loss — forgetting important things such as close relatives' names;
- confusion about where they are, who other people are, and what day or time it is;
- difficulty finding the right words, or following and understanding conversation;
- inability to concentrate and difficulty in completing simple tasks;
- loss of interest in activities they have previously enjoyed;
- mood swings, emotional disturbances and sometimes depression.
Other possible symptoms include:
- visual hallucinations (seeing things)
- loss of or increase in sex drive
- epilepsy (seizures)
Dementia is a progressive illness, meaning that the symptoms get worse over time. In the later stages of dementia you may become unaware of your plight. Your behaviour may become erratic and your personality disintegrate. These symptoms can be particularly distressing for those caring for people with dementia.
Dementia is caused by various illnesses of the brain. These cause the brain cells to die more quickly than usual, and the brain therefore shrinks and mental abilities are impaired.
There are several types of dementia with different causes.
This is the commonest type of dementia, representing about 50% of cases. It destroys cells, disrupting the chemical messengers (neurotransmitters) that carry information in the brain. This affects the memory and other mental abilities. This damage is linked to two types of abnormal protein deposits in the brain. These are plaques, which occur between brain cells, and threads of protein called tangles that develop within the cells.
This is the next most common type of dementia, accounting for 10—20% of cases. The disease is caused by damage to the blood vessels leading to the brain, which supply it with oxygen.
As the oxygen supply is cut off, brain cells die, leading to strokes. Strokes can cause severe weakness or paralysis on one side of the body. They may also cause loss of balance and disturbed vision or speech.
- Vascular dementia can occur suddenly following a stroke.
- One type, known as multi-infarct dementia (MID), develops as a result of a series of small strokes in the brain. These may seem like dizzy spells but over several months the attacks lead to greater confusion and then MID.
- A rarer type, called Binswanger's disease or subcortial dementia, is caused by diseased blood vessels deep inside the brain.
Dementia with Lewy bodies
This form of dementia, which accounts for about 15% of cases, is named after tiny spherical structures made of proteins that develop inside nerve cells in the brain. These lead to the destruction of brain tissue, affecting memory, concentration and language skills. There may also be visual hallucinations, and people with this disease can become stiff, sluggish and suffer tremors.
Over 750,000 people in the UK suffer from dementia, according to Alzheimer's Society estimates. This number is expected to grow over the next 25 years as the population ages. But dementia is certainly not inevitable.
The main risk factors are as follows.
It is rare to develop dementia before the age of 65 but the risk increases as you grow older. The chances of being affected are:
- About one in 1,000 under the age of 65
- Four to five in 100 over the age of 65
- One in five over the age of 80
Family and genetics
No single gene is responsible for Alzheimer's disease and inherited factors alone do not explain why some people develop it while others do not. But there is evidence of a genetic link in many cases.
Early onset Alzheimer's disease
"Early onset" means before the age of 65.
- A few families have a defect on chromosome 21 in a gene called amyloid precursor protein (APP). This affects the production of a protein called amyloid that has been linked to Alzheimer's when it builds up in the brain.
- A more common defect occurs on chromosome 14 and is thought to be responsible for the majority of the early onset cases of familial Alzheimer's.
About half the children of someone with one of these abnormalities inherit it and it is likely that they will go on to develop Alzheimer's. But the defect does not skip a generation, i.e. if you don't inherit it you can't pass it on to your children.
If you have three or more close relatives who developed Alzheimer's disease at an early age (between 35 and 60), your GP may refer you to a specialist called a geneticist for genetic testing for "familial Alzheimer's disease".
Late onset Alzheimer's disease
There is also a genetic link with many later cases of Alzheimer's disease. This link is weaker than in cases of early onset but it affects more people.
- About a quarter of the population inherit one copy of the ApoE4 gene, which increases your risk of developing Alzheimer's by up to four times.
- About 2% of the population inherit two ApoE4 genes, one from each parent. This makes you sixteen times more likely to develop the disease.
- 60% of us also inherit two ApoE3 genes. This is only considered to put you at "average" risk of developing Alzheimer's. About half of those with both genes develop the disease by their late 80s.
No significant link has been found between the environment and dementia. It is not caused by stress, or too much or too little mental activity, and is not infectious.
There is circumstantial evidence of a link between aluminium, mercury and Alzheimer's disease. It has been claimed there are higher levels of these metals in the brains of sufferers, but research has not proved that they cause the disease.
Aluminium has been shown to be associated with both plaques and tangles in the Alzheimer brain. But there is no clear evidence that it causes the disease.
- Tests on rabbits in the 1960s found that injecting them with aluminium caused tangle-like formations in their nerve cells. But these tangles were different from those found in the human brain in Alzheimer's disease.
- There is no risk from using aluminium saucepans or from drinking tea, which contains traces of the metal.
Mercury is known to have a toxic effect on the body's central nervous system. There is concern that the metal can escape from dental fillings, and there are moves to ban their use in several countries. These moves are based on the known toxic effects of mercury and not any fears of a link to Alzheimer's disease.
Smoking, drinking wine, taking anti-inflammatory drugs or vitamin supplements have all been advocated at times as helping prvent the disease, but there is no evidence that shows a clear link. In fact, recent research suggests that smoking might actually increase rather than reduce the risk of Alzheimer's.
More recent research suggests that controlling the risk factors heart disease such as high blood pressure, high cholesterol and being overweight could also protect the brain from dementia.
However, you can reduce your risk of developing the vascular disease and strokes that cause vascular dementia. The lifestyle changes you need to make include stopping smoking, taking regular exercise and reducing the amount of salt in your diet.
Don't worry if you occasionally forget things as you get older. It's quite normal to forget something but still remember details associated with it.
- For example, you may briefly forget your neighbour's name but still know that the person you are talking to is your next-door neighbour. Such problems are quite normal as you have more to remember. Forgetfulness is simply a nuisance for most old people and the majority will not develop dementia.
- People with dementia not only forget details but the context as well. For example, you would forget your neighbour's name and be completely unaware of who they are. Even close relatives may become strangers.
- This severe memory loss is often accompanied by other problems, such as changes in behaviour and the loss of ability to do everyday tasks.
Dementia usually takes about six months to become apparent. Your wife, partner or relatives will often be the first to notice changes in your behaviour. But you need to see a doctor to get an accurate diagnosis. They can rule out any other possible causes, such as depression. If dementia is suspected, you will probably be referred to a psychogeriatrician.
Diagnostic tests include:
- Verbal tests to decide whether your memory and other mental abilities are deteriorating. These tests will be repeated after a few months to see if there is any change.
- Brain scans (CT (computed tomography) and MRI (magnetic resonance imaging) scans) can check if other diseases such as tumours are to blame and see if parts of the brain are shrinking.
Diagnosis is usually accurate in 80—90% of cases.
There is currently no cure for dementia. Once brain cells have been destroyed they cannot be replaced, so the damage to the brain is permanent. Treatment can only temporarily delay the onset of some symptoms. The exact treatment will depend on the type of dementia you have.
Most people with dementia will be treated by a team of specialists. This may include psychogeriatricians, specialist nurses, and occupational, speech and language therapists, as well as your GP. Treatment and rehabilitation aims to restore as much physical and mental ability as possible, for as long as possible.
Drugs have been developed that can treat some of the symptoms and slow the progress of Alzheimer's disease. The brains of Alzheimer's sufferers have a serious shortage of the chemical acetylcholine, which affects nerve cell communication and memory. Drugs such as Aricept (donepezil hydrochloride), Exelon (rivastigmine) and Reminyl (galantamine)maintain the existing amount of acetylcholine by blocking the production of the enzyme acetylcholinesterase. (Acetylcholinesterase usually acts to clear away acetylcholine.) This appears to stabilise some of the symptoms of early to middle stage Alzheimer's for a limited period of time by helping the brain to make better use of healthy brain cells.
These drugs should be prescribed and monitored by a specialist, as they have side-effects that include diarrhoea, nausea, insomnia, fatigue and loss of appetite.
A newer drug Ebixa (memantime) can be prescribed to treat moderate to severe Alzheimer's disease. It acts by blocking a messenger chemical called glutamate which is produced by the brain cells damaged by the disease. Ebixa stops glutamate from producing any further brain damage and may even slow the disease process itself. At present Ebixa is only available in some areas but this could change when NICE (the National Institute of Clinical Excellence), the body which decides whether or not a drug should be prescribed on the NHS, makes a ruling on the drug in 2005.
Inflammation of the brain and HIV-related dementia appears to have become less common since the use of the drug AZT to treat HIV. One British study found only 2% of people taking AZT developed HIV-related dementia between 1982 and 1988, compared with 20% of those not taking AZT. Recent research has also shown that anti-HIV combination therapy can improve the symptoms of dementia and other neurological problems linked to HIV.
Associated symptoms of dementia such as depression, insomnia, anxiety, delusions and hallucinations can all be helped by medication. These include tranquillisers, antidepressants and anxiety-relieving drugs. Aspirin may also help to reduce the risk of strokes, which may cause vascular dementia.
People with dementia do not suddenly lose their individuality and personality as a result of their illness. Many people have only mild problems for several years.
In the past people with dementia were sometimes treated like children. But recognising the personal history, character and individuality of the affected person is important in dementia care, as it has been shown to slow the progress of the disease. Although caring for sufferers can be very stressful, they should not be patronised.
- Speech and language therapists can help some people make better use of their remaining brain cells.
- An occupational therapist specialising in mental health can help people cope better in everyday life and be safer in the home.
- Music and art therapy, aromatherapy and massage may also be beneficial.
Respite care is also available for people with dementia. This may involve going to a day centre or day hospital. As those affected become more dependent on others, they may need to go into a nursing home for two weeks at regular intervals. This will also give their relatives or other carers a welcome break.
In the later stages of dementia sufferers often need almost constant supervision. Support groups such as the Alzheimer's Society or your doctor can advise about nursing homes and home help.
Carers need support as well as sufferers. Joining a carers group can help and counselling may also be beneficial.
In the early stages of dementia there are practical ways to jog the memory: for example, keeping a diary or using a notice board for reminders.
Most people gradually progress from mild to moderate to severe dementia over about 5—20 years.
- Symptoms can be minor for several years.
- But people in the later stages of dementia often need close supervision.
- They often become entirely dependent on others.
- Most are unaware of the seriousness of their condition.
- They may need help with eating, washing and dressing and general personal care, possibly round the clock. They may become incontinent and mute and even require tube feeding.
- They may be confined to their beds and be unable to fight off infection.
Alzheimer's Society (Tel: 020 7306 0606)
CJD Support Network (Tel: 01630 673973)
Home in my Mind (Tel: 020 7435 9510)
More real people talking about living with dementia on Dipex
Have you been affected by dementia? If so, we'd like to hear about your experience and to post it on the malehealth.co.uk site. This could be useful to other men who are also affected by this problem.
Page created on January 1st, 2005
Page updated on January 17th, 2010